The present invention relates to a double balloon catheter for intra-aortic insertion at the renal hilium, aimed at the diagnosis, prevention and treatment of acute kidney failure secondary to kidney hypoperfusion and, in case of death attributed to heart arrest, for "in situ" preservation of both kidneys to be later on used as renal grafts.
The insertion of the above catheter aims at a triple target, namely; a) instant and continuous recording of hemodynamic drifts and biochemical data at the renal hilium; b) maintenance of an optimal renal perfusion pressure (above or equal to 100 mmHg) as far and as long as there might be cardiac activity and direct administering at renal level of any substance whatsoever in the aim to prevent an acute kidney failure to be suffered by the patient, and c) "in situ" preservation of both kidneys to be later on used as renal grafts, in case of death attributed to heart arrest.
The balloon catheter for aortic contrapulsation is a standard therapeutical technique in the field of the mechanical circulatory assistance of the cardiogenic shock with the aim to maintain the left ventricular activity. Such a technique involves introduction of the catheter through the femoral artery up to the thoracic descending aorta. Through the use of an electrocardiogram (ECG) for due syncronization, the 30 to 40 cms baloon inflates during distole and deflates immediately after the left ventricular ejection. The purpose of the contrapulsation aims at increasing the coronary blood flow thus raising the diastolic perfision pressure (inflation of baloon) and further decreasing the oxygen requirements by the myocardium and improving the cardiac volume of flow thus reducing poscharge (balloon deflation). The hemodynamic effects of contrapulsation consist of: increase of the diastolic pressure with a raise of the coronary flow; increase of the cardiac volume of flow (10-20%) and decrease of the left ventricular diastolic filling pressure. Contraindications involve disection or aneurysm of the thoracic or abdominal aorta.
Another baloon catheter for intra-aortic insertion has been aimed at the obtention of kidneys for further transplant, from cadaver donors dead from heart arrest. The first one to conceive this idea has been Wilson Se in 1968; however his catheter did not prove useful since it was provided with only one balloon and when perfusionning "in situ", perfusion fluid went to the limbs. The double balloon catheter was originally reported by Banowski Lh. et al although the clinical practice of the above technique was performed by Garcia-Rinaldi R. et al in 1975, who reported ten cases of functioning kidney transplants from cadaver donors dead from heart arrest.
In those countries where brain death (with beating heart) is admitted, organs for transplants are obtained from this type of cadavers; hence, the use of these catheters has been scarcely popular. It is however widely accepted in those countries where brain death is not admitted, such is the case of some European countries and Japan.
Undoubtedly, the report recently published in Clin. Transplantation (1993) by Itsuo Yokoyama et al, from the University of Nagoya (Japan) which shows the miximun experience which has ever been published on the use of the double balloon for the obtention of kidneys for transplants. It refers to 119 donors dead from heart arrest, wherein survival rate for receiver reaches 95.0% and 93.0% after 1 and 5 years respectively and the survival of the graft reaches 85.0% and 72.7% for the same 1 and 5 years respective terms. All of the above results are liable to be superposed to the best results attained from cadaver donors with beating heart.
In all cases, the insertion of the cathether is made through disection of the femoral aorta following heart arrest. Once the catheter has been inserted into the aorta, its placement is made by means of the pull-back technique, that is, by inflation of the balloons and further withdrawal, pulling down from the catheter thus fitting the lower balloon at the level of the aortic-ileac biffurcation. The mean time since the heart stops beating till the start of the kidney perfusion (hot ischemia time) used to be 12 minutes.